The effect of different flute design and torque-controlled motor on the shaping ability of simulated resin root canals

Abstract

The purpose of this study was to compare the shaping ability of the two different Ni-Ti file systems and the two different engine systems in simulated canals.A total of four groups of each 10 were tested. (Group PT). Canal preparation time was recorded. The images of pre-and post-instrumented root canals were scanned and superimposed. The amounts of increased width and centering ratio were measured and calculated at apical 1, 3 and 5 ㎜ levels.These data were statistically analyzed with one-way ANOVA and Duncan' s multiple range test The results of this study were as follows; 1. Canal preparation time of HT group was the shortest (p < 0.05). 2. The amount of increased canal width in HE group was significantly larger than PT group at apical 1 ㎜ level (p < 0.05). At apical 3 ㎜ level, PT group was significantly smaller than other groups (p < 0.05). At apical 5 ㎜ level, PE group was significantly larger than PT group (p < 0.05). 3. The amount of centering ratio in HE group was significantly larger than other groups (p < 0.05). At apical 5 ㎜ level, HT group was significantly larger than PE group and PT group (p < 0.05). Under the condition of this study, torque-controlled endodontic motor is safer than no torque controlled motor, especially when the active file is used. [J Kor Acad Cons Dent 30(6):486-492, 2005]